Bar-twister.



F. H. WILLIAMS..

BAR TWISTER.

APPLICATION FILED JUNE 24. 1912. RENEWED JULY 2i. 1911.

1 57,435. Patented Feb. 26,1918.

' 3 SHEEIS-SHEET l.

ATTORNEY F. H. WlLLlAMS.

. BAR TWISTERE APPucATwN HLED JUNE 24. m2. RENEWED JULY 21 :911.

1,257,435. Patented Feb. 26,1918.

3 SHEETS-SHEET a.

INVZNToR WITNESSES '5. M W I ATTOKIV'EX UNITED STATES PATENT OFFTCE.

FRANK H. WILLIAMS, OF BUFFALO, NEW YORK.

BAR-TWISTER.

Specification of Letters Patent. Patented Feb. 26, 1918.

Application filed June 24, 1912, Serial No. 705,390. Renewed July 21,1917. Serial No. 182,091;

To all whom it may concern:

Be it known that I, FRANK H. inmates, a citizen of the United States ofAmerica, residing at Buffalo, in the county of Erie and State of NewYork, have invented certain new and useful Improvements in Bar-Twisters, of which the following is a full, clear, and exactdescription.

My invention relates generally to devices for twisting metal bars afterthey have passed through the pass rolls of a rolling mill and preferablywhile they are still hot.

One of the main objects of my invention has been to produce a bartwister which shall twist metal bars by a rolling action.

Another object has been to provide a bar twister which shall producetwisted metal bars having a uniform degree of twist; also to provide adevice which is very simple and durable in its construction.

Moreover, my device, when twisting a metal bar, rolls the surfacethereof and thus increases the tensile strength of the bar.

Furthermore, my device may be operated either by power applied to theshafts of the rolls or by the power being applied to the bar to force itthrough the rolls.

I have accomplished the advantages above set forth by the inventionherein described, but obviously, many other advantages than those hereinset forth will be apparent to those skilled in the art.

In the drawings, which form part of this specification, like charactersof reference indicate like parts throughout the several views of which:

Figure l is a plan view of my twisting rolls showing the upper roll indotted lines and the lower roll in full lines and a bar passing betweensaid rolls.

Fig. 2 is a sectional elevation of the rolls shown in Fig. 1 and istaken on line 22 of that figure.

Fig. 3 is a fragmental section of my rolls taken on the plane 3-3 ofFig. 1 and shows the bar in one of its positions when in contact withthe rolls.

Fig. 4 is a plan view, similar to Fig. 1,'

and shows rolls of a modified form for twisting the bars of the samecross section as that shown in Fig. 1.

Fig. 5 is a plan view, similar to Fig. 1 and shows a pair ofsingle-sided rolls.

Fig. 6 is a plan view, similar to Fig. 1, and

shows rolls of a modified form for twisting a bar having a rectangularcross section.

Figs. 7 and 8 show rolls of modified forms.

The rolls in my device are mounted upon suitable shafts, journaled in asuitable housing, which shafts and housing, for clearness in thedrawings, have not been shown.

The upper and lower rolls of my device are each provided with aplurality of convex surfaces, as shown. vVhen forming these convexsurfaces on the rolls, a forming tool having a cutting edge of the sameshape as the cross-section of the bar to be twisted, is used. This toolis mounted to rotate and travel forward in the same plane and at thesame degree of twist as that of the desired degree of twist of thefinished product. The helix described by any fixed point on the formingtool makes a certain angle with the axis of the forming tool and thisangle will hereinafter be referred to as the angle of the helix. Theaxis of the forming tool is the same as the axis of the bar when beingtwisted and each of the superimposed rolls is set with itsplane ofrotation at an angle to the axis of the forming tool which issubstantially equal to the angle of the helix. Substantially half of theupper roll is angu lary disposed on one side of the said axis and thecorresponding half of the lower roll on the other side thereof, so that,the said axis bisects the angle formed by the planes of rotation of saidrolls.

The rolls when being formed are rotated in a direction opposite to thatin which they normally revolve when operating to twist the bar. Theforming tool, having its axis in coincidence with the axis of the barswhen being twisted, is now revolved and moved forward and in between therolls. The forming tool is made to follow the path of travel of apredetermined helix and as it enters between the rolls, it cuts ahelical path there-between corresponding to the shape of the cuttingedge of the tool and thus generates the convex surfaces on the peripheryof the rolls.

Thus when forming the rolls shown in Fig. 1, which are designed fortwisting a bar having a square crosssection, the side of the formingtool which first comes in contact with, for instance, the lower roll 10,first generates and cuts the convex surface 11 thereof. The corner ofthe cutting tool at the end of the first side thereof cuts the groove12; the second side of the tool cuts the convex surface 13; the nextcorner cuts the groove 1 1; the third side of the tool cuts the convexsurface 15; the third corner cuts the groove 16; and the last sidegenerates and cuts the convex surface 17. The path of travel of the partof the cut ing edge of the forming tool which contacts with the surfs.generated, is shown by the heavy dot and dash line in Fig. 1, which ismarked 38.

While the surface of the lower roll 10 is being generated and cut. theupper roll 18 (shown in dotted lines) also being operated upon by theforming tool and thus formed with convex surfaces 19, 20, 21 and 22 androoms "28, 24 and 25. The path of travel of the part of the cutting edgeof the tool which contacts with the upper roll 18 will be diametricallyopposite to the path 38 of the lower roll of Fig. 1, as well as theother forms of rolls shown.

The other forms of rollers shown are generated and cut in the mannerjust described and in each case the cutting edge of the forming tool ismade of a shape to conform to the cross section of the bar to betwisted. In each of the se eral figures is indicated, in a similarmanner to Fig. 1, the path of travel 38 of that part of the cutting edgeof the tool which contacts with the lower roll.

lhe conformation of the center portion of the rolls depends upon theangular relations of the corners of the bar, as it passes the saidCenter portion, to a vertical center line drawn through the center ofthe two superimposed rolls. The rolls shown in Figs. 1, 5 and 6. areformed for twisting a bar, the two opposite corners of which lie in thevertical center line of the rolls as the bar passes the center of said.rolls, while the rolls of Figs. a and 7 are formed to twist a bar whichhas its top and bottom faces at right angles to the said center line asit passes the same. While 1 have shown rolls for twisting a bar in thetwo positions indicated, it is obvious that wien the forming tool isinclined at any angle between the two positions mentioned, the rollswill be cut accordingly and thus the shape of the rolls may be modified.The roll shown in Fig. 8 has the center portion cut away and is providedwith a clearance recess 26, which illustrates that the said centerportion is not an essential part of the operating surface when twistingthe bar.

Fig. t shows a pair of rolls for twisting a bar having a square crosssection and these are very similar to the rolls shown in, Fig.1 exceptthat, when cutting the same, the forming tool was set so as to have itstop and bottom faces at right anglesto a vertical center line drawnthrough the center of the rolls as it passed the said center line.

Fig. 6 shows a pair of rolls for twisting a rectangular shaped bar andshows the conformation of the surfaces of said rolls for twisting a bar,he two opposite corners of which lie in a vertical center line passingthrough the center of the two rolls.

.111 Fig. 5 I have shown a pair of rolls comprising a right-handed rolland a lefthanded roll. These rolls are superimposed and disposedopposite to each other. These rolls are for twisting a bar of squarecross section and the bar bears the same relation to a vertical centerline drawn through the center of the rolls as does the bar shown inFig. 1. The upper roll 27 has convex surfaces 28 and 29 which correspondwith theconvex surfaces :21 and 22 respectively of roll 18 shown inFig. 1. The lower roll 30 is formed with convex surfaces 31 and 32,which correspond with convex surfaces 15 and 17 respectively of the roll10, shown in Fi a 1.

Fig. '7 shows a roll similar to those shown in Fig. 5 and is providedwith convex surfaces 33 and 84;, which correspond to surfaces 35 and 36of the roll 37 shown in Fig, l.

After the convex surfaces of the rolls have been generated and cut, ashereinbefore described, a bar, being passed between said rolls, willconsequently be twisted to conform to the same predetermined helix asthat of the forming tool. When the bar strikes the first convex surfaceof the rolls, as, for instance, the surfaces 11 and 19 of the rolls 10and 18, respectively, in Fig. 1, it is immediately twisted to its fulldegree of twist and as it continues to travel between the rolls itcontacts with the other convex "surfaces thereof, which convex surfacesslightly roll the surfaces of the bar and thereby increase the tensilestrength. The path of contact of the lower roll 10 with the bar as itpasses between the rolls is indicated by the heavy dot and dash line 38of Fig. 1. (Reference is to be had to Fig 3 where the said point ofcontact of the rolls with the bar is clearly shown).

It will thus be seen that practically all of the work of twisting themetal bar, comes on the surfaces of the rolls which, first come incontact with the bar to be twisted. Should these surfaces becomeexcessively worn, the point on the rolls at which the bar is initiallytwisted, will move back in between the rolls and in substantially thepath indicated by the heavy dot and dash line of the Figs. 1, 4, 5 and6.

While it is preferable to have rolls as shown in Figs. 1, 2, 1 and 6, itis obvious that the rolls shown in Figs. 5 or 7 will perform the work oftwisting with equal efficiency.

Obviously many modifications may be made from the device as herein shownand described, without departing from the spirit of my invention or thescope of the appended claims, and I do not wish to be limited to theexact embodiment herein shown and described.

Having thus described my invention, what I claim is:

A bar twister comprising two superim posed rolls, each of them beingoppositely set with its plane of rotation at an angle to the axis of thebar being twisted, which is substantially equal to the angle of thehelix of the twisted bar and having its periphery formed with aplurality of convex surfaces,

each successive convex surface from the intersection of the planespassing through the axes of the bar and rolls being of greater diameterof revolution than the next preceding convex surface, whereby saidsuccessive convex surfaces are tangent to the successively treatedtwisted surfaces of the bar.

In testimony whereof, I have hereunto signed my name in the preesnceoftwo subscribing witnesses.

FRANK H. WILLIAMS. Witnesses:

J. WM. ELLIS, WALTER H. KELLEY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. C.

